1. Field of the Invention
This invention is directed to a load carrying cradle for carrying objects which are too heavy and/or too awkward for a person to carry, and more particularly to such a cradle with a pair of wheel assemblies which are slidably movable toward and away from each other along a pair of load supports to accommodate objects of widely varying sizes.
2. Description of the Related Art
The convenient transportation of heavy and/or bulky objects by a single person has long presented a challenge to designers of personal load carrying conveyances. Of course, an almost universally used vehicle for such occasions is a standard, single-wheeled wheelbarrow. While presenting a number of advantages, such as convenient storage and maneuverability, wheelbarrows also present a number of difficulties. The nature of the single-wheeled design renders a wheelbarrow inherently unstable. A person pushing a wheelbarrow must exert considerable energy in holding up the handles to partially support the combined weight of the load and of the wheelbarrow itself. Furthermore, the requirement for the person pushing the wheelbarrow to stand directly behind the single wheel renders it virtually impossible to carry objects of substantial length or bulk.
Prior efforts at overcoming these shortcomings have included various two, three and four wheeled designs. Two wheeled carts with an elevated bed, a rear handle and a fixed rear support leg or legs are one popular approach. Such carts often use bicycle wheels for better obstacle clearance and rough ground handling. While representing a substantial improvement over single-wheeled wheelbarrows in stability and in the lifting effort required of a user, the rear-mounted handle arrangement still makes it difficult to carry lengthy objects. Furthermore, heavy objects must be initially lifted onto the elevated cart bed before being transported, and the bulky two-wheeled carts take up an inordinate amount of storage space.
Another popular load carrying vehicle is a four-wheeled dolly of the type often used in self-service lumber yards and the like. Such dollies have a low platform, which requires minimal lifting of heavy objects, and widely spaced frame supports which permit bulky objects to be carried. However, these dollies tend to be constructed of heavy gauge steel, making the dollies themselves extremely heavy, and the small free castering wheels require a smooth, firm surface for their operation. Furthermore, the fixed spacing of the frame supports means that tall, thin objects, such as doors, gates, fence sections, etc. are not adequately supported and tend to topple over. The four-wheeled dollies generally take up even more storage space than a two-wheeled cart, and are not near as maneuverable.
It is clear then, that a need exists for a convenient and versatile load carrying cradle which is capable of carrying bulky and heavy objects. Such a cradle should be stable and relatively light, easily maneuverable, and should preferably use bicycle-type wheels for ease of operation over rough surfaces. The cradle should have a low load carrying platform requiring minimal lifting of heavy objects and yielding a low combined center of gravity for increased stability, and should have upright load support frames which are adjustable to provide adequate support even for tall, thin objects such as doors, etc. The cradle should be capable of turning in a small radius and, when not in use, the cradle should be capable of convenient disassembly so that it can be easily stored.